Installation vehicle for a tidal power plant and method for the operation thereof

ABSTRACT

An installation vehicle for a nacelle of a tidal power plant having a turbine-generator unit includes at least two floating devices with a plurality of ballast tanks, the buoyancy of which is settable, a drive device acting in different directions, and a controllable fastening device for holding the nacelle. The fastening device is connected at least indirectly to a support element, which produces a connection between the floating devices. The connection between the floating devices and the support element is embodied by a detachable coupling unit or the support element includes a device for size adaptation.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation of PCT application No. PCT/EP2012/003222, entitled “INSTALLATION VEHICLE FOR A TIDAL POWER PLANT AND METHOD FOR THE OPERATION THEREOF”, filed Jul. 28, 2012, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an installation vehicle for a tidal power plant, for example for two-part plants, for which a nacelle having a turbine generator unit is fastened on a coupling device of a foundation part, which is supported against the floor of the body of water. Furthermore, a method for the operation of the installation vehicle is specified.

2. Description of the Related Art

Water turbines around which water flows freely are known for obtaining energy from a current of a body of water. They were developed for power generation from a flowing body of water or an ocean current, in particular a tidal current, to be able to dispense with erecting flood barriers. In one possible embodiment, a propeller-shaped water turbine is used, which drives an electric generator arranged inside the nacelle.

For the efficient utilization of slower currents of bodies of water, water turbines having a large rotor diameter are required. This requirement results in a complex installation in particular in the case of a site in the ocean, so that installation vehicles adapted to the respective plan have been proposed. For example, EP 1 980 670 A1 discloses a catamaran having an open central region, which is dimensioned such that a tidal turbine can be guided through. In addition, a gravity foundation, to which the tidal turbine is coupled, is transported up to the installation location on the bottom side of the catamaran. For the installation, the plant as a whole, i.e., the combination of tidal turbine and foundation part, is lowered from the catamaran, wherein the tidal turbine is guided through the central opening. The high weight to be handled of the overall plant, to which the foundation part substantially contributes, is disadvantageous in this installation method. As a result, the installation vehicle must meet a high capacity load requirement.

To be able to install particularly large tidal power plants, it has been proposed that firstly the foundation be laid with a support structure on the floor of the body of water in a first step. A coupling device is provided on the support structure, on which the nacelle having the turbine-generator unit is fastenable. For this purpose, reference is made, for example, to WO 2002/066828 A1 and WO 2004/015264 A1. These documents disclose the placement of a nacelle having a coupling pin on a tower-side coupling device implemented as a conical receptacle. The nacelle is lowered on guide cables, which are stretched between the top part of the tower and a water vehicle, which is used for the transport of the nacelle having the turbine-generator unit.

Furthermore, GB 2437533 A and GB 2447514 B describe the installation of two-part and multipart plants with the aid of a ship crane. This requires precise maneuvering of the ship vehicle and stabilized crane systems to compensate for wave movements. Both are complex for the mentioned large-scale plant parts, so that special installation ships are necessary. In addition, the time window usable for the installation is narrowly limited, since placement of the plant requires calm weather conditions and a defined, weak incident flow.

To make a crane-based installation of a two-part plant easier, it is proposed by DE 10 2008 032 625 B3 that a lifting device for a nacelle be equipped with a foldable apron, which encloses the tower in the face of the final approach to a foundation part and thus centers the lifting device in relation to the coupling device.

To be able to dispense with special installation vehicles, U.S. Pat. No. 7,859,128 B2 proposes designing a nacelle having a turbine-generator unit for a two-part plant having a positive buoyancy. For the installation, a cable connection is set up between the tower-side coupling device and the coupling counterpart on the nacelle, which draws the nacelle to the coupling device. If the cable connection is guided at the end of the coupling pin and on the base of the conical receptacle of the coupling device, automatic centering occurs upon retraction of the cable. This concept has the disadvantage of the design expenditure for the cable traction system, which remains on the plant. Furthermore, the buoyant components provided in the nacelle require additional structural space.

Alternatively, disconnectable buoyancy aids can be used for the installation, which are described by U.S. Pat. No. 3,633,369 and U.S. Pat. No. 3,823,564. Floats are disclosed, which are used for the transport and the depositing of support frames for drilling platforms. Furthermore, a method for depositing heavy loads on the ocean floor is known from GB 980,575. For this purpose, the pontoon used for the transport of the load is partially flooded and drawn with the aid of winches on an anchor system to the ocean floor. Placement without interfering wave influences is thus possible.

What is needed in the art is an installation vehicle for components of tidal power plants, for example for a nacelle having a turbine-generator unit, and also a method for the operation thereof, which is not influenced by weather and wave influences. The installation vehicle is also to be suitable for precise deposit and recovery of plants of different sizes.

SUMMARY OF THE INVENTION

The present invention provides an installation vehicle and a method of use for a tidal plant which overcomes the disadvantages of the prior art. A diving device is used as the installation vehicle according to the present invention, which receives a nacelle having a turbine-generator unit for a tidal power plant using a controllable fastening device. The installation vehicle is connected by a supply and communication line to an above-water ship. This connection line does not absorb any load, however, so that the installation vehicle is decoupled from wind and wave influences on the water surface after the diving. For an alternative embodiment, the supply line is omitted and the installation vehicle is operated as an energy-autonomous and remote controllable unit.

The installation vehicle includes at least two floating devices having a plurality of ballast tanks, which may be implemented as streamlined, oblong units. The nacelle having the turbine-generator unit is held between the floating devices by a controllable fastening device using a support element, which produces a connection between the floating devices. According to the present invention, a detachable coupling device is used for connecting the floating device to the support element and/or the support element includes a device for size adaptation, which allows setting of the spacing of the floating devices. By way of this measure, the installation vehicle according to the present invention is adaptable to different structural sizes of the turbine-generator unit. The spacing between the lateral floating devices is adapted by a replacement or a length change of the support element such that the turbine-generator unit can be securely accommodated. Accordingly, an adaptation is performed as a function of the size and/or the weight of the nacelle having the turbine-generator unit.

By setting the spacing of the floating devices and adapting the support element, which is used as a load-absorbing connection between the floating devices, an installation vehicle adapted to the respective plant to be placed results, for which bending and torsion forces are reduced on the load-absorbing structures, for example the support element. Furthermore, the maneuverability and the service life are increased as a result of the reduced load.

For a refinement of the installation vehicle according to the present invention, the floating devices are additionally adaptable in size. They may, for example, include a plurality of ballast tanks, which are arranged in a row and to each of which a device for accommodating ballast water is assigned. The water inflow advantageously occurs against a continuously maintained internal pressure, to be able to ensure rapid blowout in case of emergency. To adapt the floating devices, they consist of individual modules, wherein each module includes at least one ballast tank. Furthermore, a detachable connection, which is implemented as load-bearing, exists between adjoining modules. Replacing individual modules and adding additional modules to lengthen an advantageously implemented floating device is thus possible.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 shows an installation vehicle according to the present invention, which accommodates a nacelle;

FIGS. 2 a and 2 b show a top view of installation vehicles according to the present invention having a length-adapted support element, which produces a connection between lateral floating devices;

FIG. 3 shows the arrangement of ballast tanks for the floating device of an installation vehicle according to the present invention; and

FIG. 4 shows a subsection in a sectional view of a modularly constructed floating device of an installation vehicle according to the present invention.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIG. 1, there is shown an installation vehicle 1 according to the present invention in schematically simplified form. It is used to accommodate a nacelle 2 having a turbine-generator unit 3, which can be placed utilizing a coupling connecting piece 15 on a foundation part (not shown in detail) of a tidal power plant. Nacelle 2 is held by a controllable fastening device 7 on a support element 8. Support element 8 produces a connection between the arrangement in pairs of lateral floating devices 4, 4.1, 4.2, with the aid of which installation vehicle 1 dives in a controlled manner.

Referring now to FIG. 3, there is shown the construction of floating device 4 as a partial sectional view. Ballast tanks 5.1, . . . , 5.8 arranged in a row, which are implemented as streamlined on the ends of floating device 4, are sketched. Ballast tanks 5.1, . . . , 5.8 are connected to a compressed air and control unit 16, which separately sets the ballast water level in each individual ballast tank 5.1, . . . , 5.8. By way of this measure, the location of installation vehicle 1 under water is stabilized, wherein a weight compensation is executed in addition to the setting of the diving depth and the fixing of the horizontal location during the depositing and accommodation of the load.

Additional drive devices 6.1, . . . , 6.4, which are, for example, formed as thrusters aligned in the forward, transverse, and vertical directions, are used for the control of installation vehicle 1. Alternatively, pivotable drives or steel rudders can be used.

Floating devices 4, 4.1, 4.2 represent substantial components for the incident flow resistance because of their structural size, in spite of a streamlined design. By way of the measure according to the present invention, of configuring the transverse spacing between lateral floating devices 4, 4.1, 4.2 as adaptable, installation vehicle 1 results having a transverse extension adapted for turbine-generator unit 3 of nacelle 2 to be installed. As a result, the bending and torsion loads acting on support element 8 are minimized, so that its service life increases. In addition, installation vehicle 1 according to the present invention is more maneuverable than an oversized floating aid due to the adaptation of support element 8.

To adapt the transverse spacing between floating devices 4, 4.1, 4.2, the connection between support element 8 and floating devices 4, 4.1, 4.2 is disconnectable. For this purpose, a detachable coupling device 9.1, 9.2 having a bolt connection 12 is used to implement this connection. This detachable coupling device 9.1, 9.2 can be fastened on various fastening points 11.1, 11.2, 11.3, 11.4 on support element 8, so that different spacings for floating device 4, 4.1, 4.2 are settable on support element 8.

Alternatively, support element 8 can be replaced depending on the installation task. This embodiment is shown in FIGS. 2 a and 2 b. FIG. 2 a shows a first support element 8.1, which sets spacing d₁ between floating devices 4, 4.1, 4.2, which is less than spacing d₂ for installation vehicle 1 adapted to a larger turbine-generator unit 3. For a further alternative embodiment, a device for size adaptation 10 can be provided on support element 8, 8.1, 8.2. This can be an extension part or an extendable unit.

Referring now to FIG. 4, there is shown a refinement for an installation vehicle according to the present invention, wherein lateral floating device 4 has a modular structure. Modules 13.1, 13.2, 13.3 are sketched, which each accommodate a ballast tank 5.9, 5.10, 5.11.

Ballast tanks 5 9, 5.10, 5.11 themselves, or a structure which encloses them, are implemented as load-bearing, so that by arranging self-supporting modules 13.1, 13.2, 13.3 in a row, a size-adaptable floating device 4, 4.1, 4.2 results. Therefore, depending on the weight to be accommodated of nacelle 2 provided for the installation, the necessary overhang length in the longitudinal direction for floating devices 4, 4.1, 4.2 can be set by the selection of the module number. The modules are coupled 13.1, 13.2, 13.3 by connection components 14, . . . , 14.n, which are reachable via access openings 18.1, 18.2, 18.3, 18.4.

Further embodiments of the present invention are conceivable. The connection between floating devices 4, 4.1, 4.2 can be produced by a plurality of support elements 8, 8.1, 8.2, wherein some of the elements can run diagonally in relation to the longitudinal axis of the installation vehicle predefined by floating devices 4, 4.1, 4.2, if the region provided for accommodating turbine-generator unit 3 remains free. Furthermore, it is conceivable to implement support elements 8.1, 8.2 as a supporting frame or using of a streamlined profile, to allow improved installation under incident flow. The installation vehicle is oriented such that the longitudinal axis of lateral floating devices 4, 4.1, 4.2 is aligned as parallel as possible to the incident flow. Additional fins or rudders can be provided accordingly for the transverse stabilization.

While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

LIST OF REFERENCE NUMERALS

1 installation vehicle

2 nacelle

3 turbine-generator unit

4, 4.1, 4.2 floating device

5.1, . . . , 5.11 ballast tank

6.1, 6.2, 6.3, 6.4 drive device

7 controllable fastening device

8 support element

8.1 first support element

8.2 second support element

9.1, 9.2 detachable coupling unit

d₁, d₂ spacing

10 device for size adaptation

11.1, 11.2, 11.3, 11.4 fastening point

12 bolt connection

13.1, 13.2, 13.3 module

14.1, 14.2, . . . , 14.n connection components

15 coupling connecting piece

16 compressed air and control unit

17 supply and control line

18.1, 18.2, 18.3, 18.4 access opening 

What is claimed is:
 1. A submersible installation vehicle for a nacelle of a tidal power plant having a turbine-generator unit, the submersible vehicle comprising: at least two floating devices having a plurality of ballast tanks, a buoyancy of said plurality of tanks being settable; a drive device configured for acting in different directions and coupled at least indirectly with said at least two floating devices; a support element; a device for setting a spacing of said plurality of floating devices; and a controllable fastening device configured for holding the nacelle, said controllable fastening device being attached at least indirectly to said support element to form a connection between said plurality of floating devices, wherein at least one of: said connection between said plurality of floating devices and said support element is a detachable coupling unit; and said support element is a device for size adaptation.
 2. The submersible installation vehicle according to claim 1, said plurality of floating devices being fastenable on a plurality of different fastening points of said support element.
 3. The submersible installation vehicle according to claim 1, wherein said connection between said plurality of floating devices and said support element is a detachable coupling unit and said detachable coupling unit includes a bolt connection between said plurality of floating devices and said support element.
 4. The submersible installation vehicle according to claim 1, said plurality of ballast tanks associated with one of said floating devices are arranged in a row.
 5. The submersible installation vehicle according to claim 4, said floating devices including a plurality of modules which are individually replaceable, each of said plurality of ballast tanks being assigned to one of said modules.
 6. The submersible installation vehicle according to claim 5, said modules including a plurality of detachable connection components configured for coupling to adjacent said modules.
 7. The submersible installation vehicle according to claim 6, said at least two floating devices are adaptable in size.
 8. A method for operating a submersible installation vehicle for a nacelle of a tidal power plant having a turbine-generator unit, the method comprising the steps of: setting a buoyancy of a plurality of ballast tanks of at least two floating devices; providing a drive device connected at least indirectly with said at least two floating devices and causing said drive device to act in different directions; holding the nacelle with a controllable fastening device, said controllable fastening device being attached at least indirectly to a support element to produce a connection between said at least two floating devices; setting a spacing between said at least two floating devices by one of a replacement and a length adaptation of said support element, dependent upon at least one of a size of the nacelle and a weight of the nacelle having the turbine generator unit.
 9. The method according to claim 8, further comprising the step of constructing said at least two floating devices from a plurality of individual load-bearing modules connected to one another, said plurality of modules being adapted to at least one of a size and a weight of the nacelle having the generator unit. 